encore build internal npm install regression in CLI 1.58.5 (works on 1.58.4)

What's happening

Bumping the Encore CLI from 1.58.4 to 1.58.5 breaks the npm install that encore build docker runs internally. On CI the build dies after about a second, and the actual npm error never makes it to the log — Encore just says the build failed. That swallowed error cost us a lot of time before we figured out what was going on.

Pinning the CLI back to 1.58.4 fixes it completely, with no other change.

Environment

• Encore CLI: 1.58.5 (broken) vs 1.58.4 (works)
• Encore.ts backend (TypeScript)
• CI: GitHub Actions, ubuntu-latest, Node 18
• Command: encore build docker <image>
• CLI installed via bash install.sh <version> from encore.dev/install.sh

How to reproduce

1. Take an Encore.ts app and build the image on CI with encore build docker.
2. On 1.58.5 the internal npm install fails almost immediately and the build aborts.
3. Switch to 1.58.4 (nothing else changed) and the build goes through fine.

What we already ruled out

We rebuilt the CI environment in Docker to narrow it down, and the failure is not caused by:

• Node version (tried 18)
• Our app code or dependency changes
• Whether a package-lock.json is present — adding a lockfile and switching to npm ci didn't help on 1.58.5

The only thing that flips the result is the CLI version. 1.58.4 passes, 1.58.5 fails, same everything else.

What I'd expect

1. encore build on 1.58.5 should install dependencies the same way 1.58.4 does.
2. When the internal npm install fails, Encore should print npm's real error instead of failing quietly. The silent failure was by far the hardest part to debug.

Workaround

Pin the CLI to 1.58.4 in CI:

bash install.sh 1.58.4